it's one of the techniques that can be used: to initiate your stutter on your own, and get good at it this way. i don't know how long it takes to get results, because i gave up on it myself when i tried it... mind you, fluctuations in stutter severity is common, and i think it's gonna take quite a while to perceive if things are better. lack of eye contact is a common trait of stutterers too. i know from my own experience that it can feel terribly awkward to get used to looking people in the eyes more. but, you know, "mileage may vary" and all that.